Non-correlated indicators

[Phil Lane <logical@xxxxxxxxxxxxx>]

There was some discussion here the other day about the use of
non-correlated indicators. Seems like a very sound idea. 

Trouble is, I can't seem to see intuitively how indicator x would or would
not correlate with indicator y. Would a 3 bar MA be at all similar to a 20
bar MA? On one level of thinking, it would seem that all price-based
indicators are inherently correlated.

Would anyone care to help me master the obvious?

Thanks...